Hematuria is blood in the urine. This is not a normal finding, but it is not uncommon and, although it is often worrisome for the person who experiences it, it is not necessarily a cause for alarm. Hematuria is a sign, not a disease itself. It is an indicator that prompts a health practitioner to investigate further to try to determine the underlying cause of the blood.

Blood in urine may be easily visible or it may be present in such tiny amounts that it is only detected, for example, during a urinalysis performed as part of a routine health checkup. Urine is normally clear and a shade of yellow that varies from pale straw to light amber, depending on the concentration of the urine. The color of urine is frequently different when there is blood in it, but it may not necessarily be red.

Gross hematuria (visible) can cause urine to be pink, red, tea-colored, or coca-cola colored. In some cases, a person may have blood clots in the urine or may be able to see visible drops of blood fall into the urine in the toilet while urinating.

Microscopic hematuria (not visible with the naked eye) will not alter the color of the urine.

Many of the causes of hematuria involve the urinary tract, which consists of two kidneys, two ureters, a bladder, and a urethra.

Urine is produced continuously by the kidneys as they filter wastes out of the blood.

Urine moves from the kidneys through the ureters into the bladder, where the urine is stored, before being voided through the urethra during urination.

Various conditions that involve other systems of the body can also cause blood in the urine. For more on these, read the discussion in the section on Causes.

Some of the underlying causes of hematuria are benign, temporary states that do no lasting harm and resolve with little or no specific treatment. Some causes, however, may be critical conditions or represent a chronic condition that requires medical intervention and monitoring.

The only way to understand the seriousness of hematuria in a specific individual and to decide on an appropriate treatment is to investigate. As part of the investigation, a health practitioner will evaluate an individual's medical history, physical examination, and accompanying signs and symptoms to help determine what is causing hematuria.

This may include answering questions, such as:

Is it really blood?
One of the first questions to be asked is whether or not it is really blood that is present and/or seen in the urine.

Reddish-brown coloring can also come from eating foods such as beets and rhubarb or taking drugs such as phenolphthalein, phenothiazine, phenacetin, phenindione, etc.

Hemoglobinuria is the presence of hemoglobin in the urine. Some conditions cause red blood cells to break apart (hemolyze) and release hemoglobin, the iron-containing protein that gives red blood cells their color. The excess hemoglobin is eliminated through the urine, causing it to turn red or tea-colored. Hemolytic anemias, including sickle cell anemia for example, can lead to hemoglobinuria.

Other substances produced by the body and eliminated in the urine can change the color. For example bilirubin, which is usually removed by the liver but can accumulate when it is damaged or diseased, can cause urine to be a dark amber color. This is of concern and needs to be further investigated, but it is not hematuria. Another example is myoglobin, a small, oxygen-binding protein found in heart and skeletal muscles that is filtered from the blood by the kidneys and is excreted into the urine. High levels of myoglobin can give urine a red color, making it appear as if there is blood in the urine.

Is the blood from the urinary tract?
Contaminating blood may find its way into the urine from:

Vaginal bleeding, such as from menstruation

Hemorrhoids

Is it due to an infection?
Infections can sometimes cause cloudy, smelly urine, painful urination, and occasionally hematuria.

Is the blood from a single isolated incident or from a known cause?
Sometimes blood may appear and then go away without the cause ever being identified. In other cases, it may be from an identifiable, resolvable or self-limited cause, such as:

Strenuous exercise

Fever

Exposure to toxins, such as contrast dyes used in radiologic procedures

A medical procedure that physically involves part of the urinary tract, such as surgery, a kidney biopsy, or inserting a urinary catheter, can cause temporary bloody urine.

Physical injury to the kidney or bladder, such as trauma

An isolated incident (cause never identified)

Is the hematuria due to an inflammation or irritation of the urinary tract (or prostate in men) or due to blockage by or the passage of a kidney stone?
The following can cause blood in the urine and sometimes radiating pain, painful urination, urinary urgency, and/or urinary hesitancy:

Urethritis—inflammation of the duct that carries urine from the bladder out of the body (urethra)

Prostatitis—inflammation of the prostate (which surrounds the urethra in men)

Is it caused by kidney disease or a condition that can cause kidney damage?

There are a variety of kidney diseases that can cause hematuria. An example is glomerulonephritis, a kidney disease associated with the filtering units in the kidneys (glomeruli).

Diabetes and high blood pressure (hypertension) are common causes of kidney damage and can sometimes result in hematuria.

Polycystic kidney disease is an inherited disorder that can lead to the formation of cysts in the kidneys and can lead to kidney disease.

Is hematuria due to some other disease or condition within the urinary tract?

Structural abnormalities within the urinary tract can cause bleeding.

Blood clots can form within the urinary tract.

Is the hematuria due to some other underlying chronic and/or inherited disorder?
This may be a disorder that affects the body as a whole (systemic) or that results in excess blood within the urinary tract, leading to hematuria. Some examples include:

Bleeding disorders—these can lead to excessive bleeding episodes (bloody noses, bruising, prolonged bleeding, etc.) throughout the body. Examples include hemophilia and thrombocytopenia.

Alport syndrome—an inherited condition associated with hematuria and protein in the urine

Testing is performed to determine the extent, severity, and persistence of hematuria and to identify and address the underlying cause. Generally, a health practitioner will use an initial set of tests to confirm the presence of hematuria and identify or rule out some of the more common causes. Depending on those findings, as well as the affected person's signs, symptoms, and medical history, a more extensive workup may be done.

Laboratory Tests

Initial testing:

Urinalysis—this is typically the first test performed and the primary means by which hematuria is detected or confirmed. It consists of a visual and chemical examination that can identify gross hematuria based upon the color of the urine and by a positive finding on a chemical test strip. If there are abnormal findings, then a microscopic examination is performed. Multiple urine samples may be tested. According to the American Urological Association, microscopic hematuria is defined as > 3 red blood cells seen per high powered (microscope) field (rbc/hpf) on two of three specimens. Other findings from a urinalysis, such as the presence of protein, may give clues to the cause.

Frequently, no treatment is necessary for a single incident of hematuria or for hematuria that is self-limited, such as that due to strenuous exercise.

Treatments for other causes of hematuria are geared towards resolving or managing the underlying condition and treating any associated symptoms. For more on conditions that may cause hematuria and their associated treatments, see the Related Pages tab.

People who find blood in their urine should talk to their health practitioner about it and take the steps recommended to identify the significance, cause, and treatment best suited for their situation.

Related Images

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The kidneys are a pair of bean-shaped organs that are located at the bottom of the ribcage in the right and left sides of the spine.

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The location of the kidneys and how they work. Image credit: National Institute of Diabetes and Digestive and Kidney Diseases

NOTE: This article is based on research that utilizes the sources cited here as well as the collective experience of the Lab Tests Online Editorial Review Board. This article is periodically reviewed by the Editorial Board and may be updated as a result of the review. Any new sources cited will be added to the list and distinguished from the original sources used.

(Updated 2012 April 16). Hematuria: Blood in the Urine. National Kidney and Urologic Diseases Information Clearinghouse [On-line information]. Available online at http://kidney.niddk.nih.gov/kudiseases/pubs/hematuria/ through http://kidney.niddk.nih.gov. Accessed April 2014.

(Modified 2013 September 30). Bladder and Other Urothelial Cancers Screening (PDQ®). National Cancer Institute [On-line information]. Available online at http://www.cancer.gov/cancertopics/pdq/screening/bladder/patient/ through http://www.cancer.gov. Accessed April 2014.